Hyper-Converged infrastructure, which attracts attention recently, constructs a computer system through connection of a plurality of computer nodes (Hereinafter, merely termed “nodes”) each accommodating a server apparatus, storage apparatus, communication apparatus, and management apparatus in one enclosure. Patent Literature 1 discloses that, in the case where a firmware in a local side node starts a Direct Memory Access (DMA) controller, the DMA controller transmits a predetermined message to a remote side node, and executes an interrupt (completion notification) toward the firmware without waiting for a completion response from the remote side node.